Explanation:
What's happening to Comet Hale-Bopp's blue ion tail?
The comet's
ion tail is fluctuating more rapidly
as it passes a region of changing
solar wind.
As the comet passes from north to south, it crosses the plane of the
Sun's equator,
where the solar
magnetic field changes direction. Ions from the
solar wind,
which cause
Comet Hale-Bopp's
ion tail, act unpredictably here. Therefore,
Comet Hale-Bopp's ion tale may show unusual structure or even a
disconnection - where the tail appears to break off and then reestablish itself later. The
above
picture, taken April 30th, indeed shows unusual structure in the blue ion tail.